Data networks are sometimes shared among unrelated parties. In an apartment building, an office building, or a passenger vehicle such as an air craft or cruise ship, the occupants and passengers may have access to communication networks provided for the convenience of tenants or passengers. These networks may be part of the same data communication network that is used by the operator of the building. As an example, an office building or apartment building may have a heating and air conditioning system and a security system, all of which are controlled by a computer with wireless sensors deployed throughout the building, and tenants in the building may be provided with wireless access via the same data communications network. As another example, an aircraft or cruise ship may have a data communications system for its operations, navigation, and safety, all controlled through a network file server that is also providing wireless access to passengers. Sharing networks among unrelated parties may be cost effective and convenient but may not be secure.
For example, FIG. 1 shows a typical, prior art, data communications configuration for a passenger aircraft. An onboard network system file server (NFS) is used to facilitate data communications throughout the aircraft: between the ground controllers and flight deck, between the flight deck and the cabin, and for entertaining and for otherwise occupying the attention of passengers. This data communications system is essential for operation of the aircraft both on the ground, at the gate, and in the air. In the flight deck, this data communication system receives input from various systems throughout the aircraft, from ground control, from gate operations, from sensors, and from global positioning satellites or an inertial reference unit. This information is relayed to the flight deck instrumentation, including the captain's display, an on-board maintenance laptop, and a printer, all of which access the NFS.
In the cabin, the crew uses wireless handsets, which connect to the NFS. Passengers receive in-flight entertainment through a connectivity server and wireless access so they can use cell phones and personal electronic devices and laptops for entertainment or working, as permitted. The NFS also provides wireless internet access for the flight deck.
Thus, in the aircraft, the data communications system of the aircraft is shared between the cabin and flight deck, and between flight crew and passengers. A concern with this arrangement is that a passenger might be able to hack into the data communications system and influence the aircraft. Similar concerns may also be present in other examples of shared data communications, such as those noted above: on a cruise ship, or in an office or apartment building with multiple unrelated tenants.
One way to provide data communications is by using a broadband-over-power line (BPL) link. In BPL, an electrical power conductor is electrically coupled to a broadband network, either coupled by induction or directly to the conductor. Data may then travel over the electrical conductor simultaneously with electrical power transfer regardless of whether the power line is used for transmission of power or not. BPL applications are described in U.S. Pat. Nos. 8,948,934; 8,929,465; 7,893,557; and in US Publications 2015/0016271, 2014/0341309; 2014/0313629; 2014/0312682; 2014/0254693; 2014/0074321; and 2012/0099627 which are all incorporated herein in their entirety by reference.
A method and system that improves the security a shared data communications network beyond the current level would be an important improvement in shared data communication networks.